Chika's the successor of his family's business right? Son I think he had to get married to produce another successor so that's why the author probably just threw in the girl coz his family wouldn't want a gay son and whatnot.. honestly though I was hoping for Chika x Hotaka
Technically he does know her in a sense, because they went to school together... but yeah, I feel you. They don't know each other in any meaningful, relationship-building way. That woman doesn't truly know Chika as a person at all, she must have just been 'in love' with the idea of him since high school.
I really wonder if the manga trope of omiai/arranged marriages really still happens in Japan, even in old families with family businesses to succeed. Because seriously, Chika's situation is a way worse reason to marry someone than Masato and his ex-wife marrying because she got pregnant. (I like to think theirs was a case of an unnoticed split in the condom... because honestly, contraception is not freakin' neurosurgery. It's not hard to figure out.) And Chika was planning on this happening eventually, since the very beginning! He reminds me of Tachibana-san from Kasa No Shita, Futari.
It really bothers me that Chika is just going to marry a girl he doesn't know. It feels like the author just threw that girl in so that Chika could be "paired up" and Hotaka and Masato's love story could begin.